The present invention relates to nitrogen containing amorphous alloys and more particularly to novel nitrogen-containing amorphous alloys having a combination of superior properties as ferromagnetic materials or superconductors.
It has been known that amorphous alloys mainly composed of metal, such as Fe, Ni or Co, and semimetal or semiconducting element, such as B or Si, are superior, particularly in magnetic properties, mechanical strength, corrosion resistance, and, thus, the amorphous alloys have been greatly expected as hopeful materials in various applications, for example, as magnetic materials, electronic materials and composite materials. In response to such great expectation and demand, several methods have been developed and proposed in the production of the amorphous alloys by utilizing various combinations of alloying elements, vacuum evaporation, plating, liquid quenching etc. Among these earlier methods, for example, nitrogen-bearing alloys are disclosed in Japanese Patent Application Laid-Open Nos. 51-12310 and 54-94428.
In the former patent application, nitrogen-containing amorphous alloys are produced by melting metal in a gas atmosphere and incorporating nitrogen gas into the molten metals. In this method, amounts of nitrogen added to the alloys are at most a level of 2% and further addition could not be expected.
On the other hand, the latter produces nitrogen-containing amorphous alloys by sputtering in a chamber where plasma containing nitrogen gas of at least 2% in volume percentage is generated and nitrogen can be incorporated into the resulting alloys in appreciable amounts of 1 atomic % or more. However, in this method, it is very difficult to control so as to steadily incorporate desired large quantities of nitrogen into the alloys, since nitrogen gas is active and makes the sputtering process unstable. Further, the latter method necessitates using alloy targets which have compositions themselves capable of developing amorphous alloys and, thus, the compositions of the produced amorphous alloys are determined exclusively only by the compositions of the used alloy targets. Therefore, when other alloys with different compositions are requested, it is necessary to replace alloy targets depending upon the desired compositions, and this troublesome replacement makes the production process more complicated.